Documenti palinologici del paesaggio forestale al Monte Amiata nei sedimenti del Bacino lacustre delle lame (Abbadia S. Salvatore)

Abstract

PALYNOLOGICAL PAPERS OF M. AMIATA FORESTAL LANDSCAPE IN THE SEDIMENTS OF LE LAME LACUSTRINE BASIN (ABBADIA S. SALVATORE). — This paper deals with Le Lame lacustrine deposits (Abbadia S. Salvatore, M. Amiata area). This lake basin, like others in the same area, was located along the border of trachitic- ignimbritic terranes, variously degradated. The examined sediments have shown a large predominance of chestnut-tree. The pollinic curve of this plant undergoes some fluctuations, due to climatic pulsations emphasized by Pinus, Abies, Fagus, Betula, Carpinus, Quercetum mixtum. These genera are present in the lower part of the diagram, related to a peat bed and are more evident in the upper one. Pteridophyta spores are common and Graminaceae and Cyperaceae grains are very frequent in the lower part of the diagram. Regarding the age problem, the chestnut-tree predominance gives evidence of an age not far from Recent, although in postglacial diagrams such a high per cent is not usually found. On the other hand we can tentatively anribuie these deposits to infraglacial age, because other basins in the same area are of Riss, Riss-Würm and Würm age. The abundance of chestnut-tree can be ascribed to particularly good substratum conditions. The age problems and the chestnut-tree predominance meaning will be developed in following researches.